Synthesis and Characterization of Polyfluorenes with Light-Emitting Segments

Two new polymers consisting of poly(9-(2‘-ethylhexyl)-9-hexylfluorene) (EHH-PF) with a small amount of substituted poly( p -phenylenevinylene) (PPV) segments have been synthesized and characterized. The synthetic route was designed to allow the incorporation of only one (or zero) PPV segments per polymer chain. Photoluminescence measurements showed that energy transfer from the PF segments to the more narrow band-gap PPV segments did occur, both in solution and in film. In the solid state, all emissions were detected from the PPV segments with photoluminescence quantum yields up to 68%. One of the polymers has been used as the active material in a microcavity laser device. The threshold for lasing is 2 μJ/cm 2 .